Finished surface and process for producing same



' Patented July 18, 1933 UNITED STATES PATENT OFFICE CHARLES ELLIOTTFAWKIB, OF CHICAGO, ILLINOIS, ASSIGNOB TO PYROxYLI N PROD- UCTS,INCORPORATED, OF CHICAGO, ILLINOIS, A CORPORATION 01 ILLINOIS FINISHEDSURFACE AND PROCESS FOR PRODUCING'SAME No Drawing. Application filedJuly 9,

This invention relates to a new type of surface finish and a process forfinishing surfaces whereby a protective coating or finish is obtainedwhich is durable, and of unusually good appearance and at a cost muchbelow the cost of such coatings that are now in use.

Among the objects of my invention may be mentioned the finish of fibroussurfaces such as paper, imitation reed or fibre furniture, wood, and thelike where the material to be finished is of a porous nature, and wherein many prior instances a very large part ofthe finishing materialpenetrates into the object being finished, and leaves individual fibressticking through the surface. I wish to produce in two or three coats asmooth finish on such fibrous surfaces, by applying an adheringmaterial, glue, for example, and which material in a single coat willadhere firmly without excessive penetration, and, during drying, willpull down the individual fibres and prevent their extending through thesurface.

Furthermore, I desire to apply a very cheap material for this purpose,preferably using water as a solvent. Another-object is to have thispriming coat which gives a smooth surface and excellent adherence whenapplied to fibrous surfaces, of such a nature as to hold a subsequentfinishing coat or coats firmly bound, so that there will be no danger ofthe bond between the final finishing coats of, for example, a lacquerenamel, and the priming coat loosening and allowing the final finish topeel or otherwise loosen and separate from the glue containing coating.

The invention is especially applicable to use in finishing such surfacesas paper, wood, paper fibre, and particularly fibre articles such asfibre or imitation reed furniture. The invention will be described moreparticularly with relation to its application in the fibre furnitureindustry, although it will be understood that it is not limited in itsapplication to this particular purpose.

The use of glue size for porous or fibrous surfaces is well known andhas long been practiced. In finishing fibre furniture, for

example. it has been customaryto dip the pieces of furniture in a tankof glue solution whereby the solution penetrates the fibre,

carrying in some of the glue. The article is then drawn out of the tankand is allowed to drain. The water is allowed to evaporate leaving asmall amount of glue within the 1928. Serial No. 291,476.

fibre.v Inasmuch as the glue solution used in the clipping tank usuallycontains only about of glue, and the solution penetrates into the fibre,practically all of the glue size is down in the interstices, leaving theappearance of the surface practically unchanged. Furthermore, since thedipping tanks must be very large to accommodate large articles offurniture, the volume of glue solution in the tank is correspondinglylarge. It is necessary to hold this glue solution at temperatures abovethe jell point, that is, above the liquefaction point, of the gluesolution. Under these conditions the glue rapidly .det-eriorates, anddevelops objectionable odors, so that in a few days it becomes unfit foruse and must be discarded, thus increasing the cost of the sizingprocess.

- Even if it were vpossible to obtain a continuous glue film on afibrous surface by the dipping process, it would not be possible tosecure with glue alone good adherence between the glue surface and thesubsequent coats of finishing material such as a lacquer or varnish.

I have discovered, however, that the addition to the glue of asubstantially non-volatile substance that is soluble in both water andin the solvents used in lacquers or varnishes will render the gluesurface capable of holding, firmly bound, other finishing materials suchas lacquer, shellac, varnish, and the like. It is, of course, necessarythat the substance added to the glue be one that is compatible with boththe glue and the lacquer or varnish finishing coat. For example, whileresorcin is soluble in bothwater and organic solvents such as are usedin lacquers, it has a tendency to react with the glue to cause it tocoagulate and it therefore is not preferable for my pur pose. On theother hand, monacetin or glycerol monoacetate,

romoncnoncmmccn.)

is soluble in both water and in organic solvents and is compatible withboth the glue and the varnish or lacquer, and is therefore capable ofproducing, in a very satisfactory manner, the results which I desire toobtain, namely, a continuous coating of glueand monacetin capable offorming a bond with lacquer or varnish coatings when such coatings areapplied to the said continuous coating of glue and monacetin. A featureof my process, therefore, is a priming coat consistin of a glue-likesubstance and a substantia ly nonvolatile material which is capable ofgiving to the glue-like coating the property of adhering to subsequentfinishin g coats such as varnish, lacquer, shellac and the like. Theprocess of rendering glue suitable for use in the herein describedprocess is given in detail in my (Bo-pending application Ser. No.251,665, filed February 3, 192-8.

It has beenpreviously mentioned that in processes heretofore known orpracticed a very reat amount of glue is required, which must e appliedby a multiplicity of applications to give a continuous glue film on thesurface of fibrous material. Since this loads up and greatly stifiensthe fibre, it is not at present the practice to use so much glue as togive a continuous film on the surface, and furthermore even if such afilm were formed the adherence of subsequent finishing coats would notbe satisfactory. v

According to the preferred form of my present invention, I apply acoating of suit- .able adhesive material to the surface by a hot spray,preferably with steam.- For example, a 30 to 40% water solution of gluecontaining the proper amount of monacetin as hereinbefore mentioned andheated to a temperature above the liquefaction point of the gluesolution is sprayed onto the surface by means of a suitable spray gunsuch as is used for spraying varnish or lacquer. My preferred method ofapplying this spray of blue is to use steam instead of compressed air toatomize the glue and monacetin solution. lVhiln air that has been heatedto a temperature preferably above the liquefaction point of the glue maybe used, steam at a suitable pressure to give atomization has certainadvantages in that the particles of glue solution emitted from the spraygun do not cool down, by evaporation or otherwise, to a temperaturebelow the liquefaction or jell point of the glue solution before theycome in contact with and attach themselves to the surface to befinished. By thus holding the warm glue solution at a temperature aboveits liquefaction point until it is deposited on the surface, asmoothcontinuous film of glue and monacetin is obtained. It is to beunderstood, of course, that other suitable substances, such assulphonated castor oil may be substituted for monacetin.

Where a glue-like film is deposited by the above method, it jells veryrapidly after being deposited, and, of course, the amount which soaks inis comparatively small. Another advantage in applying the glue-likematerial by a hot spray is that a comparati vcly thick film may be builtup in one spraying operation or coat. In practice it has been found thata smooth glossy finish can be obtained by one coat even on such fibrousmaterial as blotting paper, thus giving a smooth even surface forfinishing with lacquer, shelterial to remain on the surface of theobject as a continuous film, which may be of any desired thickness.Furthermore, should any fibres extend through the surface, where it isdesirable to apply a relatively thin coat, the shrinkage during thedrying stages of the glue jell tend to pull the fibres down so as togive a perfectly smooth surface, free from projecting fibres.

It has long been realized that if an inexpensive and proper finish couldbe put on paper, cloth, felt, straw and other fibrous material, suchmaterials could be utilized to a greater extent in the fabrication ofmany articles. With my process, I can produce a finish on the surface offibrous materials, such as the above, that compares favorably with thehigh grade finishes usually obtained on smooth metal surfaces. Thuscotton braid hats can be given a finish in two coats that gives them allof the appearance of the more expensive silk or rayon braid hats.Furthermore, when the second coat is a nitrocellulose containinglacquer, the braid is rendered substantially Waterproof. Straw hats canbe given a glaze that has heretofore not been obtainable by any otherfinishing process now known. Burlap or canvas walls can be given aglossy finish by applying, by my process, one coat of my modified gluesolution and one or two coats of varnish or lacquer enamel. This has notbeen possible heretofore, except Where a great number of coats ofvarnish is used, and where a nitrocellulose lacquer enamel finish isdesired, it is necessary to use from six to eight coats in order to geta finish of an appearance that is equal to the appearance that can beobtained from a coat of modified glue and one coat of la"- queraccording to my process. It is apparent, therefore, that my inventionoffers in'nnens'e economical advantages in the art of finishing.

The following paragraphs, denoted by numerals, indicate some of theconsiderations, conditions and requirements involved in connection withthe present invention.

1. Preparation of the glue containing composzt'ion From 10 to 50 partsof glue is mixed with 50 to 90 parts of cold water and the glue allowedto swell. The swelling consists of the penetration of the water into theglue,

so that the mixture becomes jelly like. Depending upon the size of theglue particles and the grade of glue, this requires from 10 minutes to 2hours. In practice, it is usually preferable to allow the swelling tocontinue until there are no hard particles of glue remaining. Theswelled glue and water mixture is then warmed up until the liquefactionoint is reached, which is indicated by the ell turning from a jell to aliquid state, such as is well known in preparing gelatinjells. When theglue and water have completely liquefied, there is added, for example,from one to twenty parts of a compound such as monacetim'sulphonatedcastor oil, methyl or ethyl urea, and the like. If it is moreconvenient, the monacetin or other mutually soluble substance may beadded to the water in which the glue is placed for swelling. Thematerials which are suitable and desirable for this purpose arepreferably substantially nonvolatile. organic compounds which aremutually soluble in water and in organic solvents such as alcohol, butylacetate, turpentine and the like. Furthermore,

as has already been mentioned, the material should be compatible withboth glue and the materials used for subsequent coats of finish.

Where monacetin is used, it acts also as a plasticizing agent for theglue, so that where a glue plasticizer is desired it may not benecessary to add any additional plasticizer. In some cases, however, itis desirable to add additional glue plasticizer, in which case any ofthe well known glue plasticizers such as glycerin may be used. Pigments,fillers, dyes, and the like may also be added to'the glue containingsolution where this is desirable.

\ Also, where it is desirable to keep the glue solution for a period oftime, any of the well known glue preservatives may be used. Since,according to my process, only a relatively small amount of the abovedescribed.

modified glue solution need be held above the jell temperature duringits application, the glue containing composition may be kept in coldstorage over relatively long periods of time.

Various modifications are of course possible such as the addition of thematerial to the water used for swelling the glue, etc.

2. Application of the glue containing composition As before mentioned,it is desirable to apply the glue containing composition to the surfaceof the article to be finished, having only sufiicient penetration togive good adherence of the glue to the material being finished.Mypreferred method is to spraying equipments such as are used forspraying lacquers, shellac, varnish, and the like.

In any case, the most'satisfactory results are obtained when thetemperature of the glue containing solution is held above its due toevaporation of water and to the trans fer of heat from the solution tothe air between the time the spray leaves the spray gun nozzle and itreaches the surface being finished, I can employ pressure steam. The useof steam will be readily apparent, as it will readily be seen that thesteam will not only prevent evaporation from the particles of spray bymaintaining a moisture saturated atmosphere, but will give up its ownheat and maintain a temperature during the whole operation above thejell point of the glue solu tion. One of my preferred methods ofapplying the glue cont-aining material is, there fore,"the use ofpressure steam instead of air for operating the spray gun. The source ofsteam may be attached to any suitable spraying apparatus at theconnection ordinarily used for air. The steam pressure required may bethe same as the air pressure required on the spray gun to give similaratomization in the spraying of lacquers, varnishes, shellac and thelike. The glue containing solution must be held at a temperature aboveits jell temperature at the time it enters the spray nozgle. Mixtures ofsteam and air may be use Under the conditions described above, the gluecontaining solution cools very rapidly upon striking the cold surface,and jells before it is soaked into the fibrous or porous material beingfinished. The amount of penetration can be controlled by the viscosityof the glue containing solution, the temperature of the surface beingfinished, the temperature at which the glue is applied, and by the rateof application.

3. Application of final finish has already been described, enables-me tosecure extremely great adherence of such water resistant finishingmaterials as varnish or varnish enamels, nitrocellulose lacquers,shellac, and the like. These may be applied by any of the well knownmethods such as with a brush 01' with a suitable spraying equipment. Itis, of course, obvious that these water resistant coatings may be of anytype adapted to my particular purpose, namely the protection of the gluecontaining priming coat against the action of water.

It is 'to be understood that many modifications of my invention arepossible both as to the choice of materials, the proportions ofmaterials used, and the method of applying the materials to the surfacebeing finished without departing from the spirit of the invention, orexceeding the scope of the appended claims. The herein describedinvention is therefore defined by the claims.

In the following claims the term surface coating is to be interpretedsubstantially as the equivalent of protective coating, and the term glueas intended to include any adhesive-like material having the functionsand capabilities of glue in the connection herein mentioned.

What I claim is:

1. A material carrying a protective coating comprising a continuouscoating of glue and a substantially non-volatile glycerol ester and oneor more coats of a nitrocellulose containing finishing material appliedto the glue containing priming coat.

2. A material carrying a protective coating comprising a continuouscoating of glue and monacetin and one or more coats of a lacquer orvarnish finishing material applied thereto.

3. A material carrying a protective coating comprising a continuouscoating of glue and monacetin and one or more coats of ni tro-cellulosecontaining finishing material applied thereto.

4. A fibrous material carrying a tightly adhering coating containingglue and a water soluble glycerol ester and one or more coats ofcellulose ester containing finishing material including a vegetable oilapplied thereto.

5. A fibrous material carr ing a tightly adhering coating containing gue and a water soluble glycerol ester and one orv more coats ofnitrocellulose containing finishing material applied thereto. I

6. A woven fibre body carrying a tightly adhering coating comprising apriming coat of glue and a water soluble glycerol ester and one or morecoats of nitrocellulose containing finishing material applied to saidcoating of glue and glycerol ester.

7. A fibrous surface carrying a tightly adhering coating comprising apriming coat of glue, a water soluble glycerol ester and a pigment, andone or more coats of nitrocellulose containing finishing materialapplied to said glue containing priming coat.

8. The. herein described process comprising spraying a water solution ofglue and a glycerol ester to a surface as a pr1ming coat wherein steamis employed for securing atomization, allowing the glue containing coatto dry and applying thereto one or more coats a Water solution of gluean a glycerol ester A and a pigment as a priming coat on the surface ofsaid fibre furniture and wherein steam is used to secure atomization ofsaid glue containing solution, allowin the said priming coat to dry andap lying t ereto one or more coats of a nitroce lulose containingfinishing material.

11. The herein described process of finishing absorbent surfacescomprising making a water solution of glue and a substantiallynon-volatile organic substance soluble in both water and organicsolvents said solution having a jell point higher than the surface towhich it is to be applied, heating the said solution above its 'ell ointto cause it to .liquefy, applying t e iquefied glue containing solutionin its liquid condition under such conditions of temperature that saidglue solution cools and jells before it has time to be absorbed by saidabsorbent surface, allowing the glue containing coating to dry, andapply-ing thereto one or more coats of a nitrocellulose base finishingmaterial.

12. The herein described process comprising applying a solution of glueand a glycerol ester to a surface, allowing the glue containing coat todry, and apply-ing thereto one or more coats of a. cellulose estercontaining finishing material. 4

13. The herein described process compris- .ing applying a. solution ofglue and a glycerol ester to a surface, allowing the glue containingcoat to dry, and applying thereto one or morecoats of a water resistantvarnish- 14. The herein described process comprising applying a solutionof glue and a glycerol ester to a surface, allowing the glue contain-16. The herein described method of rendering glue capable of forming abond with cellulose ester base lacquers, comprising adding to a glue aglycerol ester that is soluble both vin water and in the solvents of thelacquer.

CHARLES ELLIOTT FAWKES.

